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RequestInterface – input message … Normally the client would specify either a characteristic or a (set of) tools, and the tools would be filled out by the domain interfaces Tools to use, ranked in order of preference Source and sink hosts A time specification Credentials for authorisation and authentication. This is an anyType element, for extensibility

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RequestInterface – output message foo.bar SELECT * FROM measurements WHERE id=myuniqueid The location is of type anyType, so any sort of reference can be put in here (this SQLQuery is just an example)

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ResponseInterface Takes a MeasurementRequest Returns a MeasurementRequest or one of the faults Both interfaces may add new source/sink elements: – Either may remove tool elements Either may add credentials

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More Information See http://www.hep.ucl.ac.uk/~pdm/e2epipes/d omain.html